They were apprehended last month by police and sniffer dogs at Lima airport, where 11kg of Cocaine worth £1.5m was found in their luggage disguised as food.

They are now expected to be jailed at a new hearing for six years and eight months in prison.

The pair could spend time at Santa Monica women's prison in Lima

A spokesman for the court in Callao said: "They will automatically have a sixth off from the minimum jail sentence of eight years and will be sentenced to six years and eight months in prison.

"Sentencing will take place on October 1 at a new hearing."

Reid's family has previously said they are working with the Foreign Office in the hope that the Peruvian authorities will allow her to serve part of her sentence in the UK.

Speaking outside the court in Lima, lawyer Meyer Fishman said he could not comment until the young women were sentenced.

Santa Monica prison houses 1,035 inmates - more than double the 450 it was designed for

Both women, who had been working on the Spanish party island of Ibiza this summer, had previously claimed they were coerced into carrying the drugs by Colombian drug lords who kidnapped them at gunpoint.

So far they have been held at the notorious Virgen de Fatima prison in Lima, but court officials said they may now be transferred to the equally tough Santa Monica women's jail.

Their guilty pleas came on the same day that the UN declared that Peru has now overtaken Colombia as the world's number one coca leaf producer.

Inmates have limited access to drinkable water at the jail

According to a report by the United Nations Office on Drugs and Crime, coca plantations in Peru covered 60,400 hectares last year.

Peru's national prisons institute says that 90% of the 1,648 foreigners in the country's prisons are either sentenced or awaiting trial for drug trafficking.